Backend Developer

Mactores is a trusted leader among businesses in providing modern data platform solutions. Since 2008, Mactores have been enabling businesses to accelerate their value through automation by providing End-to-End Data Solutions that are automated, agile, and secure. We collaborate with customers to strategize, navigate, and accelerate an ideal path forward with a digital transformation via assessments, migration, or modernization.

Mactores is looking for a Software Engineer with proficiency in Java, Spring, and Hibernate to participate in the migration project from Oracle to PostgreSQL. The ideal candidate should possess a robust understanding of Java, Spring, and Hibernate, with hands-on experience in developing large-scale Java web applications.

What you will do?

• Analyze and remediate large enterprise Java codebases to replace legacy or database-specific SQL constructs with modern, standards-compliant SQL.
• Convert embedded SQL within Java services and MyBatis XML mappers, including rewriting constructs such as vendor-specific functions, sequences, pagination logic, dynamic SQL, and error-handling patterns.
• Collaborate closely with schema and database migration engineers to ensure application-layer SQL aligns with the modernized target schema.
• Refactor Java transaction logic, error-handling, drivers, and ORM/DAO layers to support the behavior of modern databases.
• Participate in unit, integration, and performance testing to confirm functional parity and ensure applications meet performance SLAs post-modernization.
• Support application cutover activities for production environments, including validation, monitoring setup, rollback planning, and stabilization.
• Produce engineering documentation: SQL remediation guides, code-migration runbooks, troubleshooting guides, and knowledge-transfer material for customer teams.
• Work across distributed teams (US & India) and collaborate with customer SMEs to ensure business logic alignment and successful modernization outcomes.

What are we looking for?

• Bachelor’s degree in Computer Science, Engineering, or related field.
• 5+ years of professional Java development experience (Spring, JDBC, MyBatis/Hibernate or equivalent).
• Experience with application modernization, database migrations, or large-scale refactoring initiatives.
• Strong SQL expertise and the ability to analyze, interpret, optimize, and rewrite complex SQL used within Java applications.
• Deep understanding of JDBC, ORMs, Java transaction patterns, and database-driven application flows.
• Experience working on enterprise-grade, high-performance applications with complex data interactions.
• Strong communication skills and ability to work with global distributed teams in US time-zones.

You will be preferred if

• Experience with PostgreSQL, Aurora PostgreSQL, or modernization from legacy databases such as Oracle, SQL Server, or DB2.
• Exposure to automated code-refactoring tools or GenAI-assisted remediation workflows.
• Familiarity with CI/CD environments, performance testing tools, and observability stacks.
• Consulting or professional services experience delivering fixed-timeline modernization projects.

Key Responsibility Areas:

• Design, build and deliver Enterprise software solutions.
• Write code with standards and conventions and follow best practices.
• Encourage and lead innovation and solid lifecycle processes.
• Collaborate with development teams on work definition, estimation and prioritization
• Lead and grow as a professional software engineer.
• Full ownership of product deliveries and mentoring junior team members.
• Preparing curriculum to train junior developers for Java Web Development
• Strong client interactions to provide excellent Quality of Service.
• Owning the code base and making sure all code is reviewed and is of very high quality.
• Write and modify coding conventions and standards documents for all development

Required Skills:

Technologies/Frameworks – 

• Core Java, J2EE, 
• Spring Core and Spring MVC, Sprint Boot, Spring Security, 
• JDBC, Hibernate, RESTful APIs, SOAP WebServices
• Knowledge of JavaScript, JQuery, AJAX, HTML5, and CSS3, Angular is added advantage
• Junit or Mockito frameworks
• Maven, Git
• Knowledge Data Structures, 
• SQL, MySQL 
• Designing relational database schemas
• Basics of AWS, Cloud, Microservices

• Must have strong knowledge and experience in Agile based software development methodologies. Knowledge of an Agile tool like Jira.
• Strong knowledge of working in Integrations of 3^rd party APIs and creating the new APIs.
• Must have good knowledge of creating Flow diagrams, UMLs and all the required documentations.
• Domain Preference
• BFSI, FinTech

Work Location - Bangalore (Should be ready to relocate)

Kindly go through the JD & company details if interested please revert with below details & acknowledge with your availability.

Mode of work: Hybrid weekly 2/3 Times Mumbai/ Bangalore location.

While you may already know about Wissen and the company history, here is a quick rundown for you.

INTERVIEW PROCESS:

1. Hacker earth assessment
2. Round 1
3. Round 2
4. Final Round

About Wissen Technology:

• The Wissen Group was founded in the year 2000. Wissen Technology, a part of Wissen Group, was established in the year 2015.

• Wissen Technology is a specialized technology company that delivers high-end consulting for organizations in the Banking & Finance, Telecom, and Healthcare domains. We help clients build world class products.

• Our workforce consists of 550+ highly skilled professionals, with leadership and senior management executives who have graduated from Ivy League Universities like Wharton, MIT, IITs, IIMs, and NITs and with rich work experience in some of the biggest companies in the world.

• Wissen Technology has grown its revenues by 400% in these five years without any external funding or investments.

• Globally present with offices US, India, UK, Australia, Mexico, and Canada.

• We offer an array of services including Application Development, Artificial Intelligence & Machine Learning, Big Data & Analytics, Visualization & Business Intelligence, Robotic Process Automation, Cloud, Mobility, Agile & DevOps, Quality Assurance & Test Automation.

• Wissen Technology has been certified as a Great Place to Work®.

• Wissen Technology has been voted as the Top 20 AI/ML vendor by CIO Insider in 2020.

• Over the years, Wissen Group has successfully delivered $650 million worth of projects for more than 20 of the Fortune 500 companies.

We have served client across sectors like Banking, Telecom, Healthcare, Manufacturing, and Energy. They include likes of Morgan Stanley, MSCI, State Street, Flipkart, Swiggy, Trafigura, GE to name a few.

Website : www.wissen.com

Wissen Technology has been certified as a Great Place to Work®. The technology and thought leadership that the company commands in the industry is the direct result of the kind of people Wissen has been able to attract. Wissen is committed to providing them the best possible opportunities and careers, which extends to providing the best possible experience and value to our clients.

Job Description:

As per our conversation, please find below the job description for your review. 

·       Strong written/verbal communication skills

·       Minimum 4-14 Years of Core Java Programming with Collections Framework, Concurrent Programming, Multi-threading (Good knowledge in Executor service, Fork join pool and other threading concepts)

·       Good knowledge of the JVM with an understanding of performance and memory optimization.

·       Extensive and expert programming experience in JAVA programming language (strong OO skills preferred).

·       Excellent knowledge on collections like, Array List, Vector, LinkedList, HashMap, Hash Table, HashSet is mandate.

·       Exercised exemplary development practices including design specification, coding standards, unit testing, and code-reviews.

·       Expert level understanding of Object-Oriented Concepts and Data Structures

·       Good experience in Database (Sybase, Oracle, or SQL Server) like indexing (clustered, non clustered), hashing, segmenting, data types like clob / blob, views (materialized), replication, constraints, functions, triggers, procedures etc.

·       While you may already know about Wissen and the company history, here is a quick rundown for you.

• 3+ years of experience in the Development in JAVA technology.
• AWS or cloud Experience
• Strong Java Basics
• SpringBoot or Spring MVC
• Hands on experience on Relationl Databases (SQL query or Hibernate) + Mongo (JSON parsing)
• Proficient in REST API development
• Messaging Queue (RabitMQ or Kafka)
• Microservices
• Any Caching Mechanism
• Good at problem-solving

Good to Have Skills:

• 3+ years of experience in using Java/J2EE tech stacks
• Good understanding of data structures and algorithms.
• Excellent analytical and problem solving skills.
• Ability to work in a fast paced internet start-up environment.
• Experience in technical mentorship/coaching is highly desirable.
• Understanding of AI/ML algorithms is a plus.

Requirements: Job Description

• Excellent knowledge in Core Java (J2SE) and J2EE technologies.
• Hands-on experience with RESTful services, API design are must.
• Knowledge of microservices architecture is must.
• Knowledge of design patterns is must.
• Strong knowledge in Exception handling and logging mechanism is must.
• Agile scrum participation experience. Work experience with several agile teams on an application built with microservices and event-based architectures to be deployed on hybrid (on-prem/cloud) environments.
• Good knowledge of Spring framework (MVC, Cloud, Data and Security. Etc) and ORM framework like JPA/Hibernate.
• Experience in managing the Source Code Base through Version Control tool like SVN, GitHub,Bitbucket, etc.
• Experience in using and configuration of Continuous Integration tools Jenkins, Travis, GitLab, etc.
• Experience in design and development of SaaS/PaaS based architecture and tenancy models.
• Experience in SaaS/PaaS based application development used by a high volume of subscribers/customers.
• Awareness and understanding of data security and privacy. Experience in performing Java Code Review using review tools like SonarQube, etc.
• Good understanding of end-to-end software development lifecycle. Ability to read and understand requirements and design documents.
• Good Analytical skills and should be self-driven.
• Good communication with inter-personal skills. Open for learning new technologies and domain.
• A good team player and ready to take up new challenges. Active communication and coordination with Clients and Internal stake holder

Requirements: Skills and Qualifications

• 6-8 years of experience in developing Java/J2EE based Enterprise Web Applications
• Languages: Java, J2EE, and Python
• Databases: MySQL, Oracle, SQL Server, PostgreSQL, Redshift, MongoDB
• DB Script: SQL and PL/SQL
• Frameworks: Spring, Spring Boot, Jersey, Hibernate and JPA
• OS: Windows, Linux/Unix.
• Cloud Services: AWS and Azure
• Version Controls/ Devops tools: Git, Bitbucket and Jenkins.
• Message brokers: RabbitMQ, and Kafka
• Deployment Servers: Tomcat, Docker, and Kubernetes
• Build Tools: Gradle/Maven

We are looking for a highly motivated senior developer with at least 3+ years of strong hands-on experience in Java to join our startup. You would be playing pivotal role in contributing to the initial tech stack. You would be further responsible for designing and implementing product requirements that are highly usable, scalable, extensible and maintainable. You should be comfortable on working across different technologies/frameworks that we work on - Microservices, Java, Spring, Spring Boot, MySQL, Kubernetes, AWS.

Responsibilities and Duties:

• Design and build scalable REST APIs on Spring Boot
• Develop, test, tune for performance and deploy microservices
• Collaborate with the team, optimize and refactor the back-end architecture
• Maintain high standards of quality for code, documentation and other deliverables
• Active cross-team coordination would be expected
• Architecture and tech stack discussions to optimize for increasing server load
• DevOps tasks along with AWS features exploration

What are we looking for?

• Strong 3+ year experience in Core Java & backend technologies
• Good working knowledge of design patterns & OOAD
• Excellent analytical and problem-solving skills
• The skills that we consider: Java, MySQL/RDS, Spring/ Play, Maven, Redis, Kafka/SQS, Elasticsearch, AWS
• Experience with designing, implementing and deploying microservices
• Previously worked in a startup

Looking candidated from service base or service division of any company.
Minimum Qualification​:

• Hands-on working on Java ( {Language understanding - Java 8, Lambdas, Collections, popular frameworks & libraries}, JVM, GC tuning, performance tuning)
• Worked on REST frameworks/libraries like Spring MVC, Spring Boot, Dropwizard, REST Express etc
• Worked on Relational data stores viz. MySQL, Oracle or Postgres
• Worked on Non-relational data stores viz. Cassandra, HBase, Couchbase, MongoDB etc
• Worked on caching infra viz. Redis, Memcached, Aerospike, Riak etc
• Worked on Queueing infra viz. Kafka, RabbitMQ, ActiveMQ etc